Pyridazine

Pyridazine
IUPAC name Pyridazine
Other names 1,2-diazine, orthodiazine, oizine
Identifiers
CAS number	289-80-5 Y
PubChem	9259
ChemSpider	8902 Y
ChEBI	CHEBI:30954 Y
ChEMBL	CHEMBL15719 Y
RTECS number	GY2390000
Jmol-3D images	Image 1
SMILES c1ccnnc1
InChI InChI=1S/C4H4N2/c1-2-4-6-5-3-1/h1-4H Y Key: PBMFSQRYOILNGV-UHFFFAOYSA-N Y InChI=1/C4H4N2/c1-2-4-6-5-3-1/h1-4H Key: PBMFSQRYOILNGV-UHFFFAOYAA
Properties
Molecular formula	C4H4N2
Molar mass	80.09 g mol−1
Appearance	colorless liquid
Density	1.107 g/cm3
Melting point	-8 °C, 265 K, 18 °F
Boiling point	208 °C, 481 K, 406 °F
Acidity (pKa)	2.10
Related compounds
Related compounds	pyridine, pyrimidine, pyrazine
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Pyridazine is a heteroaromatic organic compound with the molecular formula C₄H₄N₂, sometimes called 1,2-diazine. It contains a six-membered ring with two adjacent nitrogen atoms. It is a colorless liquid with a boiling point of 208 °C.

Pyridazine has no household use. It is mainly used in research and industry as building block for more complex compounds. The pyridazine structure is found within a number of herbicides such as credazine, pyridafol and pyridate. It is also found within the structure of several pharmaceutical drugs such as cefozopran, cadralazine, minaprine, pipofezine, hydralazine, and cilazapril.